Effects of amendments on the bioavailability, transformation and accumulation of heavy metals by pakchoi cabbage in a multi-element contaminated soil
Song Li, Xiangyang Sun, Suyan Li, Yuanxin Liu, Qixue Ma, Wenjie Zhou
Abstract
extractable Cd was decreased by 33-48% after the addition of different ratios of amendments in the soil. Moreover, by increasing the content of compost and compost-biochar in combinations, easily exchangeable fractions of As, Cd, Zn and Cu were decreased, while the oxidation fraction and residual fractions were increased. When the soil amendments were applied, fresh weight of the root and shoot increased by 29-63% and 39-85%, respectively. Cd concentration in the roots and shoots of the pakchoi cabbage decreased by 21-44% and 26-53%, respectively, after adding different ratios of amendments. All the amendments were effective in reducing the Cd, Zn and Cu uptake by the roots and shoots of the pakchoi cabbage, and simultaneously reduce the absorption of As in the roots of pakchoi cabbage. As soil amendments, GWC alone or GWC + BC/GWC + HA application can significantly reduce the heavy metal levels in pakchoi cabbage while increasing the biomass production and higher application rate is more effective than the lower application rate.